Field of Invention
This invention relates to a headphones system, specifically to such system which is used in dental procedures by dental staff members comprised of office managers and dental operators, and patients to abate noise from dental tools and other apparatus present in dental operatories, while allowing communication among dental staff members and between dental operator and patients.
Prior Art
This invention consists of a pair of headphones specifically designed for dental procedures, which usually employ dental tools generating high-frequency noise, which may harm dental staff members, as well as patients. Dental procedures can be noisy due to the nature of dental tools. This constant high-frequency noise can affect the hearing capability of any dental staff member and can also be non-compliant with OSHA and NIOSH regulations regarding the maximum permissible noise exposure levels for workers in a dental facility. Over time, this noise can cause irreversible hearing loss, as well as psychological stress, to dental staff members, with serious negative effects on their quality of life and performance. In addition, this harsh environment can make patients uncomfortable, even fearful, as they are normally awake during dental procedures. A healthier environment for both dental staff members and patients can be reached by providing shielding from the noise generated by dental tools; this shielding can be achieved by using the presented pair of headphones, actively and passively abating the high-frequency noise generated by dental tools, but yet allowing the recognition of speech among dental staff members, and between dental operators and patients. The pair of headphones also allows the introduction of auxiliary audio signals including at least one of music, soothing sounds, white noise, radio, TV and/or any audio signal generated by an external audio source, with a calming or distracting effect for patients of any age.
Current use of various acoustic techniques has so far failed to provide a quiet environment for both dental staff members and patients. Various high-frequency noises generated by dental tools including at least one of dental drills, suction system, air compressors, water pick, ultrasonic scaler, and similar apparatus are variable in frequency such that pitch gets higher or lower, in amplitude such that noise gets louder or quieter, and in direction such that dental operators, patients and/or dental tools are moved in space and in time. On one hand, dental tools cannot get any quieter and on the other hand, current acoustic technologies can hardly abate the high-frequency noise generated during dental procedures.
U.S. Pat. No. 2,986,140 to Gardner et al. (1961) shows a system for noise abatement of dental procedures that is designed to relieve a patient's pain and discomfort, and, more particularly, to an effective producer of analgesic or anesthetic action resulting from a particular utilization of audible sounds. While this system provides means of relieving a patient's pain and discomfort, it does not provide such noise-abating means or communication means to dental staff members, nor allows dental operators and patients to communicate without hearing the high-frequency noise generated by dental tools.
Both U.S. Pat. No. 4,977,600 to Ziegler (1990), W.O. Pat. No. 2002/100287 A2 to Saban and Zilberman (2002) and U.S. Pat. No. 5,133,017 to Barnes, Cain, Chait and Dye (1992) show noise suppression systems for personal/patient seat. These seats have a pair of noise-suppressing speakers placed in the headrest of the chair which, based on the noise coming from the surrounding environment, generate a noise-suppressing signal that creates a quiet zone in the space surrounding the ears of the user/patient. While both systems provide a quiet zone to patients, neither are suited to provide a quiet zone for dental staff members. Similar patents are: U.S. Pat. No. 8,130,987 to Kaneda, Kishi and Shiina (2012) and U.S. Pat. No. 8,480,176 to Yamada (2013). In addition, for all the above patents, the effective communication with the patients is not allowed.
E.P. Pat. No. 0438384 A1 to Ambrosio (1991) shows a dentist chair with an earpiece sound diffusion system. This sound diffusion system comprises a music player therewith an amplifier and sound level adjusting unit. The sound diffusion system is associated with the dentist chair so that the earpieces are arranged on two sides of a headrest of the chair and provide music to the patient during the dental procedure. However, this system does not provide any sound diffusion to dental staff members nor it presents any active means of high-frequency noise suppression for the benefit of both dental staff members and patients, such as playing music to the patient does not guarantee that the high-frequency noise generated by dental tools will be cancelled.
U.S. Pat. No. 5,692,056 to Gardner (1997) and U.S. Pat. No. 6,466,673 to Hardy (2002) show an intracranial noise suppression apparatus. These devices cancel the part of the noise that is emitted to the auditory nerve via conduction through the cranial bones. While these devices may eliminate a portion of the noise coming from dental tools transmitted to the patient through bone conduction, they fail to cancel the noise transmitted to both the dental staff members and patients through the air. Another similar patent is U.S. Pat. No. 8,433,083 to Abolfathi and Spiridigliozzi (2013).
U.S. Pat. No. 5,737,433 to Gardner (1998) shows a sound environment control apparatus which allows a user, by operating a remote control unit, to selectively suppress any of all of multiple noises in his or her environment, or selectively listen to any of these while suppressing all other sounds. This apparatus requires the user to place sound detectors at each interfering sound source that the user may wish to be able to control, meaning to suppress or enhance. However, this system is not practical as no object, such as a sound detector, can be placed near the various sound sources present in dental operatories. These sound sources correspond to the dental drill, the suction system, and similar apparatus, which are all employed to the area of the mouth of the patient, which is a confined space with low visibility and does not allow for any additional device, but dental tools to be present.
U.S. Pat. No. 6,118,878 to Jones (2000) shows an active noise cancellation system for headphones with strategic microphone placement to detect a signal more similar to that incident upon the eardrum of the user. While this system provides more effective noise cancellation and improved stability, it does not allow communication among dental staff members and between dental operators and patients while in use.
U.S. Pat. No. 6,728,385 to Kvaløy, Ottesen, Henriksen, Stensby, Sørsdal, Pettersen and Svean (2004) and U.S. Pat. No. 7,246,058 B2 to Burnett (2007) show a voice detection system and discrimination system. While both devices provide efficient means to detect voice, the first device must be worn in an in-ear fashion, which is not practical and uncomfortable for both dental staff members and patients if worn for prolonged periods of time, besides being non-compliant with OSHA regulations about hygiene and cross-contamination; the second patent requires not one, but two microphones to calculate the difference in signal gain between portions of the received acoustic signals, which increases the complexity of the system, thus decreasing its reliability. A similar patent is U.S. Pat. Appl. Pub. No. 2007/0189544 to Rosenberg (2007).
U.S. Pat. No. 6,975,158 to Sekimoto (2005) shows a noise canceling circuit that uses a low-pass filter to eliminate high-frequency component contained in an input signal. While this method is effective in canceling high-frequency components of narrow and wide widths, it fails to cover all audible high-frequencies of variable amplitude in time and coming from various directions, such as the high-frequency noise generated by dental tools.
U.S. Pat. No. 7,003,099 to Zhang and Pai (2006) shows a system that cancels acoustic echo and suppresses noise. While an array microphone combined with signal processing can be effective in removing echo and suppressing noise in communication systems and voice recognition devices, it cannot be used in the dental operatory, as the head of operators and patients should be placed between the microphones of the array microphone, which would block the beam formed by the array microphone to function normally. Similar patents to this invention are: U.S. Pat. No. 6,738,482 to Jaber (2004), U.S. Pat. No. 7,403,608 to Auvray, Le Tourneur and Thomas (2008), U.S. Pat. No. 7,415,372 to Taenzer and Spicer (2008) and U.S. Pat. No. 8,315,400 to Goldstein, Usher, Boillot and McIntosh (2012).
U.S. Pat. No. 7,171,008 to Elko (2007) shows a method to reduce noise in audio systems which can be used to reduce turbulent wind-noise resulting from wind or other airjets blowing across the microphones. While this method is useful at reducing wind noise, such noise type is not present in a typical dental operatory.
U.S. Pat. No. 7,215,766 to Wurtz (2007) shows a headset with auxiliary input jack(s) for cell phone and/or other devices. While this active noise reduction system provides means for successfully integrating more than one audio source, such as a primary input signal and an auxiliary audio signal, the latter requires an auxiliary port for connection to an output of at least one device. The invention herein presented does not require any port of connection to receive the auxiliary audio signal from an external audio source. This action is done remotely.
D.E. Pat. No. 102007054051 to Schmitt-Bylandt and Tannhauser (2009) shows a method for reducing anxiety and stress of patient during dental treatment. This system is conceived to reduce anxiety by displaying an image of the patient's mouth to him/her; this solution can be counterproductive, meaning to increase the patient's anxiety instead. Additionally, the background noise is not abated, but only attenuated.
U.S. Pat. Application No. 2008/0267416 A1 to Goldstein et al. (2008) and U.S. Pat. No. 7,817,803 to Goldstein (2010) shows methods and devices for hearing damage notification and intervention. This method monitors hearing health and includes: a first acoustic sound pressure level due to an ambient audio signal; a second acoustic sound pressure level due to an emitted audio signal from a speaker; finally calculates a total sound pressure level dosage and sending a notification signal when total sound pressure level dosage is greater than a threshold value. While this system may be useful in a dental operatory, it does not allow dental staff members to communicate among each other, or dental operators and patients to communicate with each other in a high-frequency noise-free environment. A similar patent is U.S. Pat. No. 8,218,784 to Schulein, Shaw and Brown (2012).
U.S. Pat. No. 7,970,159 to Kleinschmidt, Pavlotsky and Sapiejewski (2011) shows a noise reducing headset with a pair of earcups among other components; one of the earcups has a battery door that may be opened to allow insertion and removal of the battery and covered by a yoke assembly when the headset is worn by the user, with the battery fully seated in the earcup. While this headset system offers a list of components similar to the presented invention, it fails to have a voltage source that is rechargeable. Additional patents related to the active noise reduction technique are: U.S. Pat. No. 7,277,722 to Rosenzweig (2007), U.S. Pat. Appl. Pub. No. 2009/0034748 to Sibbald (2009), W.O. Pat. 2009/135674 to O'loughlin (2009), W.O. Pat. No. 2010/107528 to Pan (2010), U.S. Pat. No. 8,073,150 to Joho and Carreras (2011), W.O. Pat. No. 2011/129934 to Hopkins (2011), U.S. Pat. No. 8,189,803 to Bergeron, Crump and Gauger (2012) and U.S. Pat. No. 8,194,873 to Pan, Cheng and Salvador (2012). The active noise reduction technique has proven to work only on cyclic low-frequency noise, such as an airplane engine or ambient noise. Dental tools generate high-frequency noise, which cannot be eliminated using this technique.
U.S. Pat. No. 8,077,874 to Sapiejewski (2011) shows an active noise cancellation system for headphones with strategic microphone placement to improve phase margin in the feedback circuit. The headset system uses active noise reduction technique which again, is primarily known to work on low-frequency cyclic noise but, not on high-frequency non-cyclic noise such as the one generated by dental tools. The presented invention uses a combination of active and passive high-frequency noise abatement instead.
“Hearing Problems Among Dental Personnel” by Khalid A. Al Wazzan et al., JPDA Vol. 14 No. 4 October-December 2005 concludes that hearing problems among dental personnel are not of a severe nature, that hearing problems can happen due to dental field noise, that dental technicians are more prone to hearing problems than other dental personnel and that incidence of hearing problems increases with the increase of daily noise exposure. Their recommendations are that the dental field team should have ear protectors to reduce the hazards of dental field noise, particularly dental technicians and those who are exposed to dental noise for long periods daily. Therefore, the invention herein presented can be applicable to dental technicians as well.